Improvement in machines for the manufacture of screws



4Sheets-Sheet'1. W. C. STIFE & .A. BOWEN. MACHINES FOE THE MANUFACTURE OF SCREWS.

No. 192,796. Patented July 3,1877.

N. PETERS, PMOTD-LITHOGRAPHEH. WASHINGTON, D C.

w Sheeis-SheetZ...

W.C.STIFF.& A.:BOW MACHINES FOR THE MANUFAC'I'UR SCREWS.

No. 192,796, Patented July a,1s 77 Sheets-Sheet a. W. I). S TIFF & A. BOWEN. MACHINES FOR THE MANUFACTURE OF SCREWS.

No. 192,795. Patented July 3,1871.

I 4'sheets-sneet4.. W. G. STIFFY& A. BOWEN. MAGHINESFOR THE MANUFACTURE OF SCREWS.

No. 192,79 Patented J'u1y? ,1871.

1+ PETERS. FHOTO LITNOGRAPHER, WASHINGTONv VD C.

UNITED STATES PATENT j O EIoE.

WILLIAM CHARLES STIFF AND ABRAHAM BOWEN, 0F BIRMINGHAM,

, 1 ENGLAND.

IMPROVEMENT INMACHINES'FORI THE MANUFACTURE OF SCREWS.

Specification forming part of Letters Patent No. 192,796, dated July 3, 1877 application filed June 22, 1877.

To all 'tvhom it may concern:

Be it known that we, WILLIAM CHARLES STIIEF, of Birmingham, in the county of Warwick, England, merchant and manufacturer, and ABRAHAM BOWEN, of Birmingham afore' said, mechanical engineer, have invented new and useful Improvements in Machinery for the Manufacture of Screws, which improvements are fully set forth in the following speci,

threaded rolls screw-threads are impressed or formed upon the rod, bar, or blank operated upon by them.

Our said invention consists in the construction and arrangement of the parts of the said machinery hereinafter described, whereby the efficient working of the machinery is more effectually secured than in like machinery as ordinarily constructed. We employ a series of three rolls of large diameter compared with the diameter of the rods, bars, or bolts to be screwed. The said rolls have-the required screw-threads formed upon them. Two of the said rolls are mounted in fixed bearings, their axes being parallel and by preference in the same horizontal plane. The other, or third, roll is situated overthe other two, its axis inwhich the axis of the lower rolls are respectively situated. The bearings of the upper roll are not fixed, but are capable of sliding vertically in slides formed in the framing of the machine. The rising and falling motion of the top roll is produced by a shaft situated over it, the said shaft carrying eccentrics, the clips of which being connected with the bearin gs of ,the said roll give the required rising and'fall- :three rolls engage. being in a plane midway between the planes.

the crank-pin of the principal shaft engages. The end of the axis of each roll has a crank,

the pins of which cranks enter the three holes, respectively, of the said plate. The cranks on the axes of the'lower rolls are of the same length as the crank on the end of the principal shaft, but. the crank of-the upper roll is capable of lengthening and shortening itself to accommodate the rising and falling of the said upper roll. This lengthening and shortening ofthe crank of the upper roll is effected by fixing the crank-pin on a slide whichworks in a groove in the crank, and by the motion ofthe said slide-inthe said groove the crankpin can take a position at a greater or less distance from the axis of the roll. The crank-pin on the said slide of the upper role engages in one of the holes in the plate carried by the crank on the principal shaft in the same way as the crank-pins of the lower rolls engage in the other two holes. 7

The action of the machine is as follows: Rotation being given to the principal shaft, its crank gives a like rotation to the three rolls through the plate carried by it in the holes, in which plate the crank-pins of the At the same time the principal shaft through the gearing described communicates a slow rotation to the shaft of the eccentrics, thereby slowly raising and lowering the top roll. The lengthening and vshortening of the crank of the top roll permits of the roll rising and falling without its rotatory motion being affected. The bar or bolt to be screwed is introduced by preference in a cold state between the rolls when the top roll is at its highest point. The descent of the top roll causes the bar or bolt to be grasped by the three rolls, by which a rotatory motion is given to it and the screw Ithreads on the rolls impressed upon it. On

the ascent of the top roll the screwed rod or bolt may be removed from the machine.

The lengthening and shortening of the crank of thetop r'o'll'maybe effected in other ways thaw the" one described. For example, the crank-pin may be fixed in the hole in the plate carried by the crank of the principal shaft and engage in a slot or groove in the crank on thetop roll with the same effect.

We w'ill now describe, with reference to the transmitted from the driving-shaft k by the accompanying drawings, the-manner in which our invention may be operated.

Figure 1 represents in side elevation a machine for the manufacture of screws containing our improvements; and Fig. 2 is a crosssection of the machine taken on the dotted line A A, Fig. 1, the top rollof the machine being represented at its highest position. Fig: 3 is an end elevation of the machine taken at the right-hand end of the machine, Fig. 1. Fig. 4'is a part elevation of the middle standardor' upright of the machine and the driving-gear of the rolls, the said Fig. 4 being taken on the line B B, Fig. 1, looking toward the'threaded rolls; and Fig. 5'is'a longitudi nal s'ection of the same. Fig. 6 is a plan, front elevation, and side elevation of the crank, crankpin, andslide, by which the top threaded roll isdriven.

In Figs. 4, 5,- and 6 the positions of the cranks andcrank -pins of the driving mechanismare different from the positions of' the corresponding parts i'n'Fig. l. The elevation,

I Fig. 1, is drawn to a smaller scale than the other figures.

The same letters of reference indicate the same parts'in the several figures of the drawmgs.

at c are the three'threadedrolls of'the machine, a b'being the pair of bottom rolls, and c the top roll, the said top roll having the position'with' respect to the bottom rolls a 1) represented in Fig. 2. The axes a b of the lower threaded rolls at turn in fixed bearings in'the uprights e 6; but the axis 0 of the topthreaded roll'c works in bearing dd, capable of sliding vertically in guides formed in the .said uprights e e, for the. purpose of giving a rising and falling motion to the said top roll, as hereinafter explained.

The rising and falling motion of the top roll a is eifected by a horizontal shaft, f, parallel to the axes of the rolls a b a, the said shalt f carrying eccentrics 'gg, which act upon clips h h, the latter being connected to.the rod t, which "passes through the sliding bearings old of the'axis of-the said top roll 0.

Motion is transmitted from the principal or driving shaft it, working in the upright e and step-bearing 6 to the shaft f, carrying the eccentrics g y, by the following arrangementof gearing: On the said driving or principal shaft 70 isa pinion, l, which gears with a toothed-wheel, m, on the parallel shaft n. Theshat't n of the toothed wheel m carries a pinion, p, which gears with a toothed wheel, g, on the shaft f of the eccentrics. By giving motion to; the shaft-f through the gearing 1m 1) q, a slow rising and falling motion is imparted by the eccentrics g g and clips h 'shaft f by the said gearing to three rotations of the principal or driving shaft k, and consequently three rotations of the threaded :rolls a b c. I

The rotatory motion of' the rolls a b 0 is following arrangement of parts: On the inner end of vthe said driving-shaft his a crank, r,

the pin r of which engages in a hole, 8, in

the middle of the circular plate t. The said plate t has in it three equidistant holes,

marked, respectively,'t "t 13, (see 'Fig.'4,) and the'end of the axis of each roll has a crank upon it, the pins of which cranks enter the three holes I? t t, respectively, of the. said plate It.

The'crank'of the axis of the rolla is marked a and its pin a; The crank of" the axis of the roll b is'marked b andits pin 1), and the crank of the top roll cis marked c and its position at a greater or less distance from the.

axis a of the said toproll c, accordingto the vertical height of the saidtop roll c'from the bottom rolls a b.

By an examination of Figs. 4, 5, and 6, it will be seen that the arrangement by which the lengthening and shortening of the crank c of the top roll 0 is effected permits ofthe top roll'c rising and falling without afl'ecting the rotatory motion of the said top roll, the said top roll rotating at the same speed as the bottom rolls a b. i g 1 Instead of efl'ecting the lengthening and shortening of the crank of the top roll 0 by the arrangement described and represented, the same object may be attained by fixing the crank pin of the said crank c on the plate 15, and causing the said crank-pin to en'- gage in a slot or groove in the crank 0 In this arrangement the slide 0 is dispensed with.

By the rotation of the principal shaft k a like rotatory motion is transmitted through the plate t and cranks andcrank-pinsafid, b b, 0 a, to the three rolls a b' c, the top roll 0 being at the samev time slowly raised and lowered by the eccentrics and clips g It, op"- eratedfrom the shaft f,and thel'att'er driven by the gearing hereinbefore described. When the top roll'c is at its. highest point, as represented in Figsrl and 2, the bar,rod,

-or blank to be screwed, marked a in Fig.2,

is introduced between the three rolls ab 0. By the descent of the said top roll'c the'bar, rod, or blank u is grasped between theithree rolls, by which a rotatory motion is communicated to it, and the screw-threads on the said rolls impressed upon the said bar, rod,

or blank.

Onthe ascent of the top roll 0 the screwed rod or bolt u may be removed from the machine, and another rod or blank introduced and screwed in the manner described.

Having now described the nature of our invention, and the manner in which the same is to be performed, we wish it to be understood that we do not limit ourselves'to the precise details hereinbefore described and illustrated, as the same may be varied without departing from the nature of our invention; but

We claim as our invention- 

